Personal care manufacturers are making thinner and more discreet products for consumers while, at a minimum, maintaining the product overall performance. This requires manufacturers to use higher amounts of superabsorbent materials (SAM), also known as absorbent gelling materials, and less pulp fibers than they have with conventional products.
Products with a high content of superabsorbent material tend to experience problems that are not encountered in products with low superabsorbent content. One such issue is poor superabsorbent containment. For example, in an absorbent core having a high quantity of SAM and a low amount of fibers, there may be insufficient fibers to hold or capture the SAM in the structure and to prevent the SAM from falling outside the core. This poor SAM containment issue could happen with structures having high SAM content under both dry and wet conditions. As an additional issue, poor structure integrity may lead to gel blocking. Gel blocking can be seen as a phenomenon in which SAMs pack themselves in the interstitial spaces in the core structure as the SAMs undergo rearrangements or deformation due to external forces from a wearer. This rearrangement of the SAM can result in lack of void volume available in the absorbent core, which can lead to poor intake of bodily fluid.
Manufacturers have been attempting to resolve these issues by incorporating thermoplastic binder fibers or hot melt adhesive in absorbent core structures to provide some attachment between SAMs or SAMs and fibers. These approaches may restrict the swelling of the SAMs and, thus, reduce the overall absorbency performance of the absorbent core. Also, these approaches often require use of large amounts of binder fibers and/or adhesives to sufficiently hold the structure together, which may undesirably result in increased stiffness of the absorbent pad.
There is thus a need, or desire, for a superabsorbent material that is capable of providing both wet and dry adhesion. There is a further need, or desire, for an absorbent pad that is thin and has good wet and dry structure integrity without compromising its absorbency performance. There is yet a further need, or desire, for a method of coating superabsorbent materials to achieve a superabsorbent material that is capable of delivering multiple functions.